Imaging plays a key role in streamlining medical procedures. It encompasses various imaging modalities and procedures to produce high-quality images of the human body. The main purpose of radiology or medical imaging is to detect, diagnose, and test abnormalities and health conditions respectively.
For many years, medical imaging is used to improve public health across different population groups. Research shows medical imaging techniques like MRI and fMRI are useful in the follow-up of illnesses already diagnosed and treated.
It is essential to know that imaging techniques for medical purposes involve a team of qualified health professionals. The team usually includes doctors, radiologists, technologists, radiographers, sonographers, and nurses. Most often, the team also includes medical physicists, biomedical engineers, and support staff.
All these health professionals work collaboratively to optimize the overall well-being of patients. Thus, we won’t be wrong to say that medical imaging is a multidisciplinary approach.
In today’s article, we will talk about MRI, fMRI, and the differences between these two medical imaging techniques. It is important to read this post thoroughly so that you understand the vital information and get the most out of it.
What is MRI?
Magnetic resonance imaging or MRI is a sophisticated imaging method to see the internal structures of the body. The primary purpose of using the MRI technique is to get a clear image of the anatomy.
Likewise, health professionals use them to detect diseases and abnormal conditions. MRI does not use the type of radiation or waves used for computer tomography (CT) scans and x-ray exams.
In general, MRI scans require the utilization of specialized equipment that uses a magnetic field with radiofrequency energy and a computer to produce clear images of the inside of the body.
How it is performed?
During an MRI diagnostic test or exam, a patient is required to stay still so that the machine can produce the clearest images. Most often, children find it difficult to stay still on the machine.
That’s why a doctor may give them sedation, which is either administrated orally or intravenously. Research shows that sedation is also helpful for adults and those who have claustrophobia.
A team of health professionals will help the patient lie down on the table, which slides into the machine. It slides through a large magnet that has a tube-like shape. Sometimes, the doctor will place a plastic coil around the patient’s head.
After the table slides into the MRI machine, a doctor or technician will take a few photos of your brain, liver, heart, or any other organ. Remember, the procedure will take some time, and if you are not feeling well inside the machine, you can use the microphone installed in the machine to communicate with the staff.
Normally, the diagnostic procedure takes 30-60 minutes. A patient may receive a contrast dye, such as gadolinium intravenously to allow the machine to see some parts of your body clearly and easily, especially the blood vessels.
Keep in mind that the MRI machine makes loud banging noises during the diagnostic procedure. That’s why the staff will instruct you to wear earplugs so that you can block the loud noises of the machine. Also, you can listen to music during the procedure.
Research studies have highlighted that there are no risks with the MRI. However, some patients may have allergic reactions due to the injection of a contrast agent. A patient must tell the staff if he or she has decreased kidney function. It is not safe to use a contrast agent for those who are suffering from kidney disorders.
If a patient is suffering from renal failure and undergoes an MRI test, a doctor must not give him the contrast agent. Even if the patient receives the agent intravenously, he or she must undergo dialysis as soon as possible to flush this out.
What is fMRI?
Functional MRI or fMRI follows the same principle as regular MRI. However, during a functional MRI procedure, the scanner and computer take photos of the brain activation over time. For instance, fMRI can produce different images of the human brain due to different activities in it.
When a certain part of the brain active, the cells or tissues in that area need more oxygen to perform their usual neural activity. It means the brain requires an increased blood flow to that particular region.
fMRI measures the differences in the volume of the blood in the brain when a person does a task at one time and he or she is resting at another time. The computer produces a coloured map of the most active areas of the brain during the task.
How it is performed?
The procedure of fMRI is similar to that of the regular MRI. It requires the patient to lie face-up on a flat table or surface, which is rolled into a tubular machine. Remember, the procedure is simple, painless, and safe. Like a regular MRI, some people may feel bothered by noises or feel claustrophobic during the scans.
Once the patient is inside the machine, the doctor gives him instructions that are seen by the patient through a pair of high-quality glasses. These glasses are somewhat similar to virtual reality headsets. For patients, the task is pretty simple and easy. For example, the doctor will instruct the patient to squeeze his left hand or think of certain words.
The active regions of a patient’s brain, which light up in the machine are combined with regular MRI photos of the brain anatomy. Once a technologist maps out those basic functions, he or can help a surgeon to determine a safe approach for removing a brain tumour or lesion.
Some research studies have highlighted that the primary difference between the two processes is that during a functional MRI, the medical staff give the patient some instructions and ask him to complete brain exercises.
These are silent exercises that increase activity in certain parts of the brain and increase blood flow to them. An increased flow of blood means the brain areas are receiving more oxygen.
Such activity in the brain lights up the photos created by the machine, giving health professionals a visible record of a map that displays the patient’s brain. When it comes to a normal MRI of the brain, it lasts between 20-30 minutes. However, a functional MRI can take up to one hour.
Differences between MRI and fMRI
We are living in a fast-paced world surrounding by high-quality and cutting-edge technology tools. Currently, many types of innovations are made and modified to make the process of diagnosis easy and simple. The purpose is to simplify the diagnostic procedures and determine abnormalities a lot easier.
Generally, diagnostic tools use machines or biological studies. In some cases, imaging tools use both machines and biological studies. Imaging is one of the most common ways to study the internal organs and diseases that can’t be seen with naked eyes. In the laboratory, technicians use different types of sources to make imaging possible, such as magnetic fields, electricity, and radiant to name a few.
One type of imaging tool that uses both electrical and magnetic sources of energy is magnetic resonance imaging or MRI. With a few modifications in the technology, scientists developed a machine out of the MRI, which is known as the functional MRI. Let us talk about the differences between these two technologies, scans, or machines.
MRI is a high-quality and powerful machine used for brain structure imaging. An MRI scan helps uncover some unnoticed structural anomalies caused by a traumatic event or a disease process.
Compared to CT scans that can’t detect the existing problem, doctors use MRIs to accurately diagnose the issue and make a treatment plan. MRI is also used for research purposes to determine anatomical differences and behavioural correlations.
On the other hand, a functional MRI is a technology that produces high-quality images through blood oxygen levels or blood flow measurements. FMRI is mainly used to collect relevant data based on the consumption of oxygen by brain tissues.
FMRI scan is a modern procedure that views an image of the brain’s active area by picking up the increased blood supply. It is known as the “Blood Oxygen Level Dependence.” So, it is important to understand that an MRI produces images of the anatomical structure of the brain while a functional MRI views the metabolic function.
When it comes to technology advancements, a functional MRI is starting to build up and gradually becoming popular among health professionals. On the other hand, MRI has already established a name for itself as it is one of the most widely used procedures in the medical field. Moreover, a functional MRI is most often used for experimental purposes, unlike sophisticated MRI.
The measurement of signals is different for both MRI and fMRI. For instance, an MRI analyzes the hydrogen nuclei of the water molecule whereas a functional MRI measures the levels of oxygen.
Research studies show that in atomic physics, the structural imaging of the MRI analyzes the differences between types of tissues with respect to space. In contrast, functional MRI imaging views the differences between tissues with respect to time.
Moreover, you must understand that magnetic resonance imaging is a high and spatial resolution while functional magnetic resonance imaging is a long-distance and temporal resolution.
When it comes to the cost of the machine, MRI is much more affordable than fMRI machines. The reason fMRI is more expensive than the MRI machine is that it comes with additional hardware and software components.
The price can sometimes reach up to thousands of dollars, and that is a lot of money. That’s why hospitals and clinics prefer MRI machines because it is a more affordable choice. Keep in mind that neither an MRI nor a functional MRI has advantages over the other because both procedures are used for different purposes.
Let us summarize the main differences between the technologies in the following table.
|Differences between MRI and fMRI|
|Views the anatomical structure of the brain or any other organ in the human body.||Produces images of the metabolic functions of the brain, particularly the active areas.|
|Studies the hydrogen nuclei of the water molecule.||Measures the levels of oxygen.|
|Identifies differences between tissues with respect to space.||Determines differences between tissues with respect to time.|
|It has a spatial resolution.||It has a superior, long-distance, and temporal resolution.|
|A widely used procedure in the medical world to produce high-resolution images of internal structures of the body.||Despite technological advancements, fMRI is used mostly used for experimental purposes.|
|An affordable and reliable machine for health institutions.||FMRI machines come with additional hardware equipment and software programs that cost more money to hospitals and clinics.|
Are MRI Scans Safe?
Research shows that millions of patients across the world have undergone MRI diagnostic procedures. It is one of the safest imaging technologies or procedures for health institutions. Studies highlight that MRI is safe for infants, children, and adults.
However, it is essential to follow the guidelines while performing the procedure. Precautions are necessary and health professionals are required to make sure they are taken.
Generally, an MRI diagnostic procedure produces no pain and causes harm to tissues of any kind. It is a safe procedure for both short-term and long-term diagnostic exams. It is essential to take precautions to ensure no metal enters the machine.
The powerful magnet of the machine can attract a few metal objects. Typically, they are known as “ferromagnetic” objects that cause them to move fast towards the magnet. This can be dangerous for the patient inside the magnet.
Therefore, it is essential to go through the metal detector to avoid taking metals of any kind to the exam room. At the same time, the doctor is required to perform the screening process carefully and prevent any metallic objects from entering the magnetic area.
The MRI tube or bore is usually small for the patient, which means it can be problematic for claustrophobic individuals. The rule of thumb is that claustrophobic patients must not undergo an MRI scan. Moreover, acoustic noise inside the machine is loud and can reach 113 dB in some scanning environments. The normal amplitude is around 90 dB inside the MRI scanner.
Although 90 dB is below the FDA’s guidelines that permit acoustic noise levels of 140 dB, experts recommend that doctors should provide ear protection equipment to the patient. In the case of young children, health professionals should use a high-quality headphone system that can reduce the MRI noise by at least 30 dB. A quality headphone can bring down the noise to normal levels – i.e. the level of adult conversation.
Are fMRI Scans Safe?
Most functional MRI scans are performed after a diagnosis. The resulting images help health professionals and patients decide about the surgery. Generally, doctors perform the scans 24-48 hours before a scheduled surgery.
It allows surgeons to get the most accurate and complete images of a patient’s brain before the surgical procedure. A functional MRI helps neurosurgeons to prepare for surgery and allows them to navigate to the correct area successfully.
Like MRI, a functional MRI is a non-invasive, painless, and safe procedure. Research studies have not highlighted any significant health risks associated with the procedure. However, the patient must not have any electronic or metal implants to undergo the procedure.
The reason is that fMRI uses a powerful magnetic field for image production and can cause problems for patients with implants. Furthermore, there was no method to locate a person’s motor or language skills center before the invention of fMRI.
The only method used previously was brain stimulation during an operation or invasive angiographic examinations. Both methods would require the patient to stay awake to respond to questions. With fMRI, doctors and surgeons can get this information easily before the surgery that can make the operation safer, faster, and more accurate.
Advancements in medical imaging have truly revolutionized the field of healthcare. Medical imaging is crucial in a wide range of health settings and different levels of medical care, such as public health, preventive medicine, palliative care, curative care, and diagnostics.
Although the clinical judgment of a doctor is sufficient for the treatment of various health conditions, the use of medical imaging techniques like MRI and fMRI can streamline the diagnosis and treatment, especially in surgical procedures.
With improved health policy and the increasing availability of MRI and fMRI, the number of brain imaging procedures is increasing significantly. Both MRI and fMRI are high-quality, safe, and effective procedures that help health professionals to produce clear, accurate, and high-resolution images of the brain.
Although fMRI is more expensive than MRI, this imaging technique can help doctors make informed decisions and reduce the number of unnecessary procedures. For instance, doctors can avoid certain surgical interventions with diagnostic imaging tools like MRI and fMRI.